Tank clouded up over night?

So most of my clean up crew died over the last few weeks so i started getting a little cyano outbreak. This morning when I got up to feed my tank was cloudy like a I had just added sand. I checked all the params and did a 15% water change.

Params before water change:

S.G. 1.025
Nirate 0ppm
Phospahtes 0ppm
ALK 9-10dKH
Calc 320ppm
Mg 1400
Params after:

S.G. 1.025
Nitrates 0ppm
Phos 0ppm
ALK 12dkH
Calc 420ppm
Mg 1400

I also cleaned my skimmer like normal. Did my monthly change on carbon and GFO. Any ideas what could be wrong?

 

Sounds like a bacteria bloom. Did a large snail, fish, or anemone die? The bacteria population will self-correct so I wouldn't worry about it assuming you have plenty of aeration. (Remember that bacteria respire too). In fact, your corals are loving this. Bacterioplankton is one of the major food sources for corals.

 

do you have macro? my tank (and every thing in it) died from a macro algae bloom.

 

Thanks for the help inwall and thats the word i was looking for a bacteria bloom and a few large turbos have died within the last week so that could be it. Aeration I should have plenty i think about 5270gph of flow in my 75gph tank. Ill keep a watch on my tank and see what it does. Thanks again.

 

No macro algae not even a sump on my tank and that is terrible everything died.

 

did it stay cloudy for long? my 60 is cloudy every once and awhile if my female cinnamon gets moody and fans up a bunch of sand. stays that way for a good few hours...

 

The bacteria bloom just happened this morning, it is still cloudy

 

Its all cleared up today thanks again inwall